1. Field of the Invention
The invention relates to a trailer connector and trailer for use in a truck and trailer combination for carrying elongated self-supporting loads, in particular to logging trucks and the like.
2. Prior Art
Truck and trailer combinations for carrying elongated self-supporting loads have been used for many years, particularly as logging trucks. In the past, logging trucks were used extensively on narrow and winding logging roads and, because the bends in such roads were often relatively tight, it was essential that the rear wheels of the trailer followed closely the tracking arc of the front wheels of the tractor when negotiating the bends. Modern logging trucks use a telescopic trailer reach or compensator that extends rigidly forwardly from the trailer and is hinged to a hitch disposed rearwardly of the truck bunk. The truck bunk and trailer bunk are both swivelling bunks and thus tend to be somewhat unstable when the truck travels at high speeds on the highway. The reach carries negligible tensile loads when the logging truck is loaded and serves mainly to force the rear wheels of the trailer into an arc that approximates to the front wheels of the tractor as the truck negotiates a curve. Nowadays logging roads have been improved considerably, ie. widened and straightened, and commonly semi-trailers or flatbed trailers can use the main logging roads without much difficulty. Consequently, trailer reaches as commonly used for rear wheel tracking purposes are often not required.
Because trailer reaches are relatively heavy components, ie. about three thousand to four thousand pounds, they detract from payload of the truck. It is well known to use a rear trailer to support a rear end of a self-supporting load with no connection between the rear trailer and tractor apart from braking and electrical service conduits. A "non-connected" trailer of this general type is used on modern highways to transport excessively long rigid loads, such as beams for bridges, buildings, etc. When the load is loaded onto the tractor and trailer, considerable care must be exercised to ensure that the wheel axles of the trailer are disposed normally to the central axis of the tractor and trailer combination to ensure accurate tracking of the rear wheels of the combination.
Commonly, when loading this "non-connected" type of tractor/trailer combination, several hours might be required to adjust the relative disposition of the rear trailer by lateral shifting and swivelling to ensure accurate wheel alignment. Whilst such loading time might be acceptable for transporting special loads where transportation costs are not a major consideration, in the logging industry where short turn around times are essential for economical operation, such excessive loading time would be uneconomic. A common logging truck with a telescopic reach can be loaded within minutes with no difficulty in maintaining wheel alignment, and thus, prospective competitive arrangements should be equally quick to load.